Pressure effect on magnetic behavior and lattice softening in CeCo4B

Abstract We have performed thermal expansion studies of CeCo 4 B at pressures up to 13 kbar and magnetization studies up to 11 kbar in the field range up to 50 kOe at temperatures between 5 and 300 K. The transition temperature, T t , of the iso-structural transition is defined by the maximum of the linear thermal expansion coefficient. T t increases with pressure ( T t =122 K at ambient pressure) and reaches the value T t =190 K at 12 kbar. A significant lattice softening is observed. The anomalies observed in the thermal evolution of the magnetization at temperatures close to T t are significantly enhanced under pressure. The pressure induced changes in the hybridization of the 3d–4f states and the changes in the antiparallel alignment of the Ce and Co moments are considered to be at the origin of the observed peculiar behavior of CeCo 4 B under pressure.